The present application relates to a photodynamic diagnosis apparatus, a photodynamic diagnosis method and a device usable therefor.
In general, as tumor cells are immature, porphyrin-based substances are easily bonded to lipoproteins in the cells, and porphyrin-based substances are slowly excreted from the cells to outside. By making full use of the characteristic and utilizing a difference between the excretion speeds of healthy cells and the tumor cells, when a porphyrin-based drug is intravenous injected, there can be provided a drug concentration difference between the healthy cells and the tumor cells. Thus, a tumor selected drug is born. Furthermore, by utilizing a photochemical action where a light energy is externally added to the drug and the drug is excited to provide fluorescence, the drug is developed into a photosensitizer for visualizing the drug concentration difference. Examples of the photosensitizer include Laserphyrin (see http://www.info.pmda.go.jp/go/pack/4299404D1028_1_05/). A diagnosis by a combination of the photosensitizer and a light is called as a photodynamic diagnosis, and has been utilized in a wide variety of clinical areas.
Photodynamic diagnosis apparatuses in the related art mainly sequentially irradiate a light from a laser or a lamp, measure fluorescence obtained by the photosensitizer, and determine tumors. However, according to the related art technology, there is no choice to determine the tumor cells only by a fluorescence intensity. In the photodynamic diagnosis, an improvement of an accuracy of tumor determination or an establishment of a diagnosis index other than information about the drug concentration read from the fluorescence intensity becomes one of important technologies. Japanese Patent Application Laid-open No. 2011-218149 and Japanese Patent Application Laid-open No. 2008-43383 relate to such technologies.